Thirsty for Blood

You’ve probably seen vampires in movies or video games. But bloodthirsty creatures exist in real life too! About 30,000 species of animals feast on blood, including insects, birds, mammals, and fish. 

Blood isn’t hard to find—it pumps through 

the bodies of all kinds of animals. “But there are many adaptations animals need to feed on blood,” says Sebastian Kvist, a biologist at the Royal Ontario Museum. For instance, bloodsucking creatures have special body parts to pierce the skin of other animals and draw blood. Many also have chemicals in their saliva called blood thinners that keep blood from clotting as they feed.  

Here are five animals that feed on blood—and how they get their liquid meals!

You’ve probably seen vampires in movies. But bloodthirsty creatures exist in real life too! About 30,000 animal species drink blood. They include insects, birds, mammals, and fish.

Blood isn’t hard to find. It pumps through all kinds of animals’ bodies. “But there are many adaptations animals need to feed on blood,” says Sebastian Kvist. He’s a biologist at the Royal Ontario Museum. Bloodsucking creatures have special body parts. They use them to pierce other animals’ skin. Many creatures that drink blood also have chemicals in their spit. They’re called blood thinners. The chemicals keep blood from clotting as the animals feed.

Here are five animals that feed on blood. Learn how they get their liquid meals.

Leeches are worms that live in ponds and oceans on every continent. These parasites 

drink the blood of animals like birds, fish, and even humans! 

Most leeches have round mouths with three jaws and up to 300 sharp teeth. They attach their mouths to the skin of a host and move their jaws side to side to make a cut. Leeches usually suck blood for 45 minutes, but some stay on their hosts for weeks. Super-stretchy skin lets the worms draw up to 10 times their weight in blood.

These adaptations make leeches useful in medicine! Some leeches are used to treat diseases and increase blood flow after certain surgeries. The powerful blood thinners in their saliva have been used to make medications.

Leeches are worms. They live in ponds and oceans. They’re found on every continent. These parasites drink animals’ blood. Those animals include birds, fish, and even humans!

Most leeches have round mouths with three jaws. They also have up to 300 sharp teeth. Leeches’ mouths attach to the skin of a host. Their jaws move side to side to make a cut. Leeches usually suck blood for 45 minutes. Some stay on their hosts for weeks. Leeches have stretchy skin. It lets them drink up to 10 times their weight in blood.

These adaptations make leeches useful in medicine! Some doctors use leeches to treat diseases. The worms also help increase blood flow after surgeries. Leeches’ spit contains powerful blood thinners. It’s used to make medicines.

Vampire finches are fist-sized birds that live on two of the Galápagos islands in the Pacific Ocean. They normally eat seeds and insects. But when those run low, they feed on the blood of other birds!

The finches work together to attack large seabirds. One finch hops on the seabird’s back and pecks at its skin to make a wound. Other finches wait for their turn. They don’t drink enough blood to harm their victims.

The blood diet gives vampire finches an edge over other finch species when food is scarce. As a result, vampire finches are the most numerous finches on the islands.

Vampire finches are fist-sized birds. They live on two of the Galápagos Islands. They’re found in the Pacific Ocean. The birds normally eat seeds and insects. But sometimes those run low. Then the finches feed on the blood of other birds!

The finches work together. They attack seabirds. One finch hops on the bird’s back. It pecks at its skin to make a wound. Other finches wait for their turn. They don’t drink enough blood to harm their victims.

The blood diet helps vampire finches when food is scarce. It gives them an edge over other finches. That’s why there’s more vampire finches on the islands.